Well, I got another one to add. Don't know if you will find it helpful, but maybe there is something that strikes a chord. I think everyone in a longer relationship has gone through this phase, where the sex decreases for a while. Sward and I did that pretty early on in our relationship. It started during second year and lasted till the third.
A problem of mine is focus. I am able to focus on nearly everything thinkable up to a point, where I am thinking constantly over this special topic, viewpoint, theme, situation, novel, game, … the list is endless. If I got this thought process started once, I just stop if I get the feeling that I 'am through' with it. It is extremely hard to get my mind occupied with something else during that time. And the last thing I think about is sex during these phases. I still got this problem today, the last time it happened, it was with Lin. I was thinking about a novel I just read and the themes that where presented during class and how great it would fit the topic I wanted to write a paper about and despite the oh-so-sweet NRE phase and such, I was just occupied otherwise and he really had to work to get my thoughts focused on him
The problem between Sward and I was that I just outright rejected him. I wasn't uninterested in sex or intimacy per se, it was just always the wrong moment as far as I was concerned. I can be too blunt, especially when it's such a delicate topic like this. His reaction was that he retreated more and more until we stopped having sex at a point. I got a really hard phase during that time (apprenticeship as specialist for Hotel and Catering Services, the hours of work were insane), tired, stressed out, occupied with work stuff and personal things. And I didn't know about my own workings. Therefore all I noticed was that he didn't seem interested anymore, because he stopped initiating.
We didn't change anything back then. We just got through this phase somehow and it was a real long one. It ended when I noticed that this was unbearable and I got focused on sex instead … yes the focus works the other way round as well
When this happens now, persevering and sensitive persistence is the way to go for us. I need some time to shift my focus, Sward learned it the hard way, I was able to tell Lin directly because I learned how I work from the experiences with Sward.
I have to second SNeacail. One of the problems that added to this, was that we are so different biorhythm wise. Sward wakes up at 4 or 5 in the morning and goes to bed at 7 or 8 pm if it's his normal weekly schedule. I am never really mentally awake before 11 am and am normally staying up till 3 or 4 am if I am able to use my time freely. Therefore the time when we were in the mood, were vastly different. I don't have the problem with Lin, we have similar rhythms.
This were two points that came to my mind. I hope it went well for you two and you got some things sorted out.